scholarly journals Growth of nanoporous high-entropy oxide thin films by pulsed laser deposition

2022 ◽  
Author(s):  
Huiming Guo ◽  
Xin Wang ◽  
Alexander D. Dupuy ◽  
Julie M. Schoenung ◽  
William J. Bowman
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Film Surface ◽  
Laser Deposition ◽  
High Entropy ◽  
Columnar Grains ◽  
Average Size

AbstractHigh-entropy oxides (HEO) with entropic stabilization and compositional flexibility have great potential application in batteries and catalysis. In this work, HEO thin films were synthesized by pulsed laser deposition (PLD) from a rock-salt (Co0.2Ni0.2Cu0.2Mg0.2Zn0.2)O ceramic target. The films exhibited the target’s crystal structure, were chemically homogeneous, and possessed a three-dimensional (3D) island morphology with connected randomly shaped nanopores. The effects of varying PLD laser fluence on crystal structure and morphology were explored systematically. Increasing fluence facilitates film crystallization at low substrate temperature (300 °C) and increases film thickness (60–140 nm). The lateral size of columnar grains, islands (19 nm to 35 nm in average size), and nanopores (9.3 nm to 20 nm in average size) increased with increasing fluence (3.4 to 7.0 J/cm2), explained by increased kinetic energy of adatoms and competition between deposition and diffusion. Additionally, increasing fluence reduces the number of undesirable droplets observed on the film surface. The nanoporous HEO films can potentially serve as electrochemical reaction interfaces with tunable surface area and excellent phase stability. Graphical abstract

Size Effect in Germanium Nanostructures Fabricated by Pulsed Laser Deposition

1999 ◽  
Vol 581 ◽  
Author(s):  
K.M. Hassan ◽  
A.K. Sharma ◽  
J. Narayan ◽  
J.F. Muth ◽  
C.W. Teng ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Band Gap ◽  
Quantum Confinement ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Wide Band ◽  
Laser Deposition ◽  
Island Growth ◽  
Wide Band Gap ◽  
Average Size

ABSTRACTWe have fabricated Ge nanostructures buried in AlN and Al2O3 matrices grown on Si(111) and sapphire substrates by pulsed laser deposition. Our approach involved three-dimensional island growth of low band-gap material followed by a layer of wide band-gap material. The nanodots were uniformly distributed in between alternating layers of AlN or Al2O3. It was observed that these nanodots exhibit crystalline structure when grown at 300-500 °C. The average size of Ge islands was determined to be ∼5-15 nm, which could be varied by controlling laser deposition and substrate parameters. The Raman spectrum showed a peak of the Ge-Ge vibrational mode downward shifted upto 295 cm− which is caused by quantum confinement of phonons in the Ge-dots. The photoluminescence of the Ge dots (size ∼15nm) was blue shifted by ∼0.266 eV from the bulk Ge value of 0.73 eV at 77 K, resulting in a distinct peak at ∼1.0 eV. The spectral positions of both E1 and E2 transitions in the absorption spectra at room temperature and 77K shift toward higher energy as the Ge dot size decreases. The interpretation of these behaviors in terms of quantum confinement is discussed in this work, and the importance of pulsed laser deposition in fabricating novel nanostructures is emphasized

scholarly journals Combined pulsed laser deposition and non-contact atomic force microscopy system for studies of insulator metal oxide thin films

2018 ◽  
Vol 9 ◽  
pp. 686-692 ◽  
Author(s):  
Daiki Katsube ◽  
Hayato Yamashita ◽  
Satoshi Abo ◽  
Masayuki Abe
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Metal Oxide ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Film Surface ◽  
Laser Deposition ◽  
Combined System ◽  
Force Microscopy ◽  
Atomic Force

We have designed and developed a combined system of pulsed laser deposition (PLD) and non-contact atomic force microscopy (NC-AFM) for observations of insulator metal oxide surfaces. With this system, the long-period iterations of sputtering and annealing used in conventional methods for preparing a metal oxide film surface are not required. The performance of the combined system is demonstrated for the preparation and high-resolution NC-AFM imaging of atomically flat thin films of anatase TiO2(001) and LaAlO3(100).

Preparation and electrical properties of CuInSe2 thin films by pulsed laser deposition using excess Se targets

2010 ◽  
Vol 25 (10) ◽  
pp. 1936-1942 ◽  
Author(s):  
Deuk Ho Yeon ◽  
Bhaskar Chandra Mohanty ◽  
Yeon Hwa Jo ◽  
Yong Soo Cho
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Surface Coverage ◽  
Hole Concentration ◽  
Pulsed Laser ◽  
Deposition Process ◽  
Laser Deposition ◽  
Average Size

An effective way to prepare a robust CuInSe2 (CIS) target for subsequent vapor depositions of thin films is suggested in this work. The technique involves addition of excess Se to presynthesized CIS powder followed by cold pressing and sintering at a temperature as low as 300 °C. Phase-pure chalcopyrite CIS films were prepared at a substrate temperature of 300 °C from targets that contained different amounts of excess Se. The average size of particulates, typical of the pulsed laser deposition process, and their surface coverage decreased with increasing Se content up to 50 wt% in the targets. Films grown from the target with 50 wt% excess Se exhibited a hole concentration of ˜3 × 1019 cm−3 and a Hall mobility of ˜2 cm2/Vs. With the decrease of substrate temperature to room temperature, the resistivity increased from 1.1 × 10−1 to ˜7.5 × 108 Ω·cm, which is attributed to the potential contributions of Se interstitials, CuIn, and VIn defects.

scholarly journals Structural, Magnetic and Gas Sensing Activity of Pure and Cr Doped In2O3 Thin Films Grown by Pulsed Laser Deposition

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 588
Author(s):  
Kamatam Hari Prasad ◽  
Karuppiah Deva Arun Kumar ◽  
Paolo Mele ◽  
Arulanandam Jegatha Christy ◽  
Kugalur Venkidusamy Gunavathy ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Gas Sensing ◽  
Magnetic Hysteresis ◽  
Pulsed Laser ◽  
Film Surface ◽  
Laser Deposition ◽  
X Ray ◽  
In2o3 Film ◽  
Average Grain Size

Pure In2O3 and 6% Cr-doped In2O3 thin films were prepared on a silicon (Si) substrate by pulsed laser deposition technique. The obtained In2O3/In2O3:Cr thin films structural, morphological, optical, magnetic and gas sensing properties were briefly investigated. The X-ray diffraction results confirmed that the grown thin films are in single-phase cubic bixbyte structure with space group Ia-3. The SEM analysis showed the formation of agglomerated spherical shape morphology with the decreased average grain size for Cr doped In2O3thin film compared to pure In2O3film. It is observed that the Cr doped In2O3thin film shows the lower band gap energy and that the corresponding transmittance is around 80%. The X-ray photoelectron spectroscopy measurements revealed that the presence of oxygen vacancy in the doped In2O3film. These oxygen defects could play a significant role to enhance the sensing performance towards chemical species. In the magnetic hysteresis loop, it is clear that the prepared films confirm the ferromagnetic behaviour and the maximum saturation value of 39 emu/cc for Cr doped In2O3 film. NH3 gas sensing studies was also carried out at room temperature for both pure and Cr doped In2O3films, and the obtained higher sensitivity is 182% for Cr doped In2O3, which is about nine times higher than for the pure In2O3 film due to the presence of defects on the doped film surface.

Asymmetric rocking curve study of the crystal structure orientations for BaTiO3 thin films grown by pulsed laser deposition

1998 ◽  
Vol 136 (3) ◽  
pp. 173-177 ◽  
Author(s):  
Chunling Li ◽  
Dafu Cui ◽  
Yueliang Zhou ◽  
Huibin Lu ◽  
Zhenghao Chen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Rocking Curve
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